scholarly journals Compartmentation of ATP:Citrate Lyase in Plants

2000 ◽  
Vol 122 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
Dhandapani Rangasamy ◽  
Colin Ratledge
Keyword(s):  
Atp:Citrate Lyase

Regulation of lipid accumulation in oleaginous micro-organisms

2002 ◽  
Vol 30 (6) ◽  
pp. 1047-1050 ◽  
Author(s):  
C. Ratledge
Keyword(s):  
Filamentous Fungi ◽  
Lipid Accumulation ◽  
Fatty Acid Synthase ◽  
Sole Source ◽  
Mucor Circinelloides ◽  
Storage Lipids ◽  
Atp:Citrate Lyase ◽  
The Stability ◽  
Micro Organisms ◽  
Single Cell Oils

A small number of eukaryotic micro-organisms, the oleaginous species, can accumulate triacylglycerols as cellular storage lipids, sometimes up to 70% of the biomass. Some of these lipids, particularly those containing high proportions of polyunsaturated fatty acids of nutritional and dietary importance, are now in commercial production; these are known as single-cell oils. The biochemistry of lipid accumulation has been investigated in yeasts and filamentous fungi and can now be described in some detail: lipid accumulation is triggered by cells exhausting nitrogen from the culture medium, but glucose continues to be assimilated. Activity of isocitrate dehydrogenase within the mitochondrion, however, now slows or even stops due to the diminution of AMP within the cells. This leads to the accumulation of citrate, which is transported into the cytosol and cleaved to acetyl-CoA by ATP:citrate lyase, an enzyme that does not occur in non-oleaginous species. This enzyme is therefore essential for lipid accumulation. The presence of this enzyme does not, however, explain why different species of oleaginous micro-organisms have different capacities for lipid accumulation. The extent of lipid accumulation is considered to be controlled by the activity of malic enzyme (ME), which acts as the sole source of NADPH for fatty acid synthase (FAS). If ME is inhibited, or genetically disabled, then lipid accumulation is very low. There is no general pool of NADPH which can otherwise be used by FAS. The stability of ME is therefore crucial and it is proposed that ME is physically attached to FAS as part of the lipogenic metabolon. ME activity correlates closely with lipid accumulation in two filamentous fungi, Mucor circinelloides and Mortierella alpina. When ME ceases to be active, lipid accumulation also stops. No other enzyme activity shows such a correlation.

Mechanisms controlling lipid accumulation and polyunsaturated fatty acid synthesis in oleaginous fungi

2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Kobkul Laoteng ◽  
Milan Čertík ◽  
Supapon Cheevadhanark
Keyword(s):  
Fatty Acid ◽  
Environmental Control ◽  
Acid Synthesis ◽  
Fatty Acyl ◽  
Conclusive Evidence ◽  
Physical Parameters ◽  
Oleaginous Fungi ◽  
Industrial Sectors ◽  
Atp:Citrate Lyase ◽  
Membrane Bound

AbstractPolyunsaturated fatty acids (PUFAs) are functional lipids that have been widely incorporated into several industrial sectors. Apart from animal- and plant-derived origins, oleaginous fungi belonging to Mucorales have been identified as promising alternatives for production of n-3 and n-6 PUFAs. It was found, in Mucorales fungi, that ATP:citrate lyase, acetyl-CoA carboxylase and malic enzyme trigger lipid overproduction, and biosynthesis of PUFA requires membrane-bound desaturases with fatty acyl substrate specificities. Accumulation of PUFAs in the cells is associated not only with the desaturation system, but it is also tightly bound with acyltransferases that facilitate the distribution of newly synthesized PUFA to individual lipid structures. Several physical parameters, such as temperature, aeration, and nutrient regimes, greatly affect either the lipid content or fatty acid composition among different Mucorales species. Conclusive evidence showed that the PUFA production yield of the fungi depends on the environmental control of “oleaginous” enzymes, and on the transcriptional expression of the desaturase genes. These valuable studies provide perspectives with biological rationale for microbial production of economically important lipids.

The distinctiveness of ATP:citrate lyase from Aspergillus nidulans

2002 ◽  
Vol 1597 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Ian P. Adams ◽  
Stephen Dack ◽  
F.Mark Dickinson ◽  
Colin Ratledge
Keyword(s):  
Aspergillus Nidulans ◽  
Atp:Citrate Lyase

Variant cDNA Sequences of Human ATP:Citrate Lyase: Cloning, Expression, and Purification from Baculovirus-Infected Insect Cells

1997 ◽  
Vol 9 (1) ◽  
pp. 133-141 ◽  
Author(s):  
Kenneth A. Lord ◽  
Xin-Min Wang ◽  
S.Jill Simmons ◽  
Robert C. Bruckner ◽  
Jane Loscig ◽  
...  
Keyword(s):  
Insect Cells ◽  
Expression And Purification ◽  
Cdna Sequences ◽  
Atp:Citrate Lyase ◽  
Infected Insect

scholarly journals Pathogen-induced expression of plant ATP:citrate lyase 1

FEBS Letters ◽  
2001 ◽  
Vol 488 (3) ◽  
pp. 211-212 ◽  
Author(s):  
Mi Chung Suh ◽  
So Young Yi ◽  
Sanghyeob Lee ◽  
Woong-Seop Sim ◽  
Hyun Sook Pai ◽  
...  
Keyword(s):  
Induced Expression ◽  
Atp:Citrate Lyase

Enhanced lipid accumulation in the yeast Yarrowia lipolytica by over-expression of ATP:citrate lyase from Mus musculus

2014 ◽  
Vol 192 ◽  
pp. 78-84 ◽  
Author(s):  
Huaiyuan Zhang ◽  
Luning Zhang ◽  
Haiqin Chen ◽  
Yong Q. Chen ◽  
Wei Chen ◽  
...  
Keyword(s):  
Yarrowia Lipolytica ◽  
Mus Musculus ◽  
Lipid Accumulation ◽  
Over Expression ◽  
Atp:Citrate Lyase ◽  
Yeast Yarrowia Lipolytica

Possible regulatory roles of ATP:citrate lyase, malic enzyme, and AMP deaminase in lipid accumulation by Rhodosporidium toruloides CBS 14

1985 ◽  
Vol 31 (11) ◽  
pp. 1000-1005 ◽  
Author(s):  
Christopher Thomas Evans ◽  
Colin Ratledge
Keyword(s):  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Energy Charge ◽  
Molecular Size ◽  
Rhodosporidium Toruloides ◽  
Regulatory Control ◽  
Central Position ◽  
Amp Deaminase ◽  
Atp:Citrate Lyase

The properties of ATP:citrate lyase, malic enzyme, and AMP deaminase have been investigated in Rhodosporidium toruloides CBS 14. ATP:citrate lyase had a molecular size of 480 000 daltons and apparent Km for citrate and ATP of 0.19 mM and 0.15 mM, respectively. The enzyme was inhibited by ADP, glucose 6-phosphate, palmitoyl-CoA, and oleoyl-CoA. [Formula: see text] ions showed a 95% stimulation of activity at nonsaturating concentrations (0.1 mM) of citrate. Malic enzyme had a molecular size of 205 000 daltons and an apparent Km for malate of 0.7 mM. The enzyme was only weakly inhibited by citrate, pyruvate, oxaloacetate, and ATP but no metabolite was found which exerted a significant regulatory control over the enzyme. However this enzyme could be used as the principal, if not sole, source of NADPH needed for fatty acid biosynthesis. The role of this enzyme and the central position of malate as a key metabolite in determining how lipid accumulation could be initiated and then sustained is discussed. AMP deaminase was detected in low activities but was fourfold higher in nitrogen-limited cells. The possible role of this enzyme in degrading AMP, regulating cellular energy charge, and supplementing [Formula: see text] pools in this yeast is also discussed.

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